No description available.

No description available.

Pancreatic ductal adenocarcinoma is a highly desmoplastic tumour, and non-malignant stromal cells contribute to progression and treatment resistance. Inflammatory cells in particular are known drivers of carcinogenesis, and macrophages are one of the most abundant inflammatory leucocytes. Therefore, exploring how macrophages drive tumour progression in pancreatic cancer would not only aid in understanding disease biology but could also offer insight to novel treatment strategies. Results presented in this thesis show macrophages secrete factors that drive epithelial-to-mesenchymal transition, promote invasion and lead to expression of checkpoint inhibitors. To determine what factors were driving this phenotype, the serine protease inhibitor SerpinB3 was initially explored, as it was highly upregulated in cancer cells cultured with conditioned media from macrophages. However, SerpinB3 gene overexpression and knockdown did not confirm a direct role for this gene in mediating migration and invasion. Further investigation revealed macrophages were secreting the cytokine oncostatin M, which was driving a metastatic phenotype through activation of the STAT3 pathway. Expression of oncostatin M receptor was upregulated in cancer cells following culture with macrophage conditioned media and conferred a worse prognosis in patient samples. STAT3 pathway activation by oncostatin M led to increased invasion in vitro, particularly of the highly tumourigenic cancer stem cell population, and increased metastasis in vivo. Moreover, oncostatin M mediated expression of the immune 'checkpoint' inhibitors on the surface of pancreatic cancer cells. Using antibody and small molecule inhibitors, reversion of these signalling pathway effects were seen and preliminary data from in vivo assays showed decreased metastasis formation with cytokine receptor antibody inhibition. Overall, the findings in this thesis contribute to emerging knowledge of how tumour associated macrophages drive tumour progression in pancreatic adenocarcinoma. Not only do they promote invasion and metastatic potential through oncostatin M secretion, but also potentiate inherent biological properties of cancer stem cells and assist in immune tolerance. In addition, results provide preliminary data to support a rationale for clinical targeting of macrophage-derived oncostatin M in pancreatic cancer.

No description available.

Ovarian cancer accounts for more deaths than all other gynaecological cancers taken together. The 5 year survival rate can be as high as 80% for cases diagnosed early, but the asymptomatic nature of the disease means that it is most frequently detected in the later stages. By this time, disease has invariably spread beyond the ovaries and the survival rate drops to around 30%. Treatment of ovarian cancer often fails due to a high rate of chemoresistance and novel methods of treatment and detection are required to increase the survival chances of patients. This study sought to determine whether gene therapy for sporadic ovarian cancer could offer a novel and more successful treatment option for the disease. Mutation or abnormal expression of the p53 gene has already been shown to be the most common genetic even in ovarian cancer, being involved in up to 70% of cases. Wild-type p53 was delivered, using liposomes, into p53 mutant ovarian cancer cell lines and this resulted in a restoration of the wild-type functions of the gene, namely cell cycle arrest and apoptosis. The results from the cell line studies suggested that restoration of the wild-type p53 function limit or reduce tumour progression and increase the sensitivity of the tumour to chemotherapy. A mouse model of human peritoneal ovarian cancer was then constructed and the wild-type p53 gene was administered in liposomes into the peritoneum. The results suggested that p53 gene therapy prevents tumours from growing in the mice, when compared to a control gene. It is now known that p53 gene therapy for humans is being clinically assessed. There are a proportion of tumours that do not harbour an abnormal p53 gene, raising the possibility that other tumour suppressor gene mutations may play a role in the molecular genetic control of growth arrest and apoptosis. P53-dependent, apoptosis-regulating family members bcl-2 and bax were analysed immunohistochemically to determine their involvement in ovarian cancer. Both proteins were significantly associated with malignancy and also with overall length of survival, but not associated with the various prognostic factors such as stage and differentiation of tumour. It is unlikely that these genes will become targets for gene therapy in ovarian cancer. Mutation, deletion and hypermethylation of the p53-independent pi6 gene, alter its function, resulting in loss of G1 cell cycle arrest control. The status of methylation of the pi 6 promoter in ovarian tumours was determined and combined with mutation data, resulting in the conclusion that abnormal pi 6 was not a common event in ovarian cancer and is therefore not a likely candidate for gene therapy. This study has contributed to the evergrowing wealth of knowledge on the molecular genetic events of ovarian cancer, and has shown that gene therapy for sporadic ovarian cancer as a clinical application is feasible.

Glioblastoma is a highly malignant tumor which mostly recurs locally around the resected contrast enhancement. However, it is difficult to identify tumor invasiveness pre-surgically, especially in non-enhancing areas. Thus, the aim of this thesis was to utilize multimodal MR technique to identify and characterize the peritumoral progression zone that eventually leads to tumor progression. Patients with newly diagnosed cerebral glioblastoma were included consecutively from our cohort between 2010 and2014. The presurgical MRI sequences included volumetric T1-weighted with contrast, FLAIR, T2-weighted, diffusion-weighted imaging, diffusion tensor and perfusion MR imaging. Postsurgical and follow-up MRI included structural and ADC images. Image deformation, caused by disease nature and surgical procedure, renders routine coregistration methods inadequate for MRIs comparison between different time points. Therefore, a two-staged non-linear semi-automatic coregistration method was developed from the modification of the linear FLIRT and non-linear FNIRT functions in FMRIB’s Software Library (FSL). Utilising the above mentioned coregistration method, a volumetric study was conducted to analyse the extent of resection based on different MR techniques, including T1 weighted with contrast, FLAIR and DTI measures of isotropy (DTI-p) and anisotropy (DTI-q). The results showed that patients can have a better clinical outcome with a larger resection of the abnormal DTI q areas. Further study of the imaging characteristics of abnormal peritumoural DTI-q areas, using MRS and DCS-MRI, showed a higher Choline/NAA ratio (p = 0.035), especially higher Choline (p = 0.022), in these areas when compared to normal DTI-q areas. This was indicative of tumour activity in the peritumoural abnormal DTI-q areas. The peritumoural progression areas were found to have distinct imaging characteristics. In these progression areas, compared to non-progression areas within a 10 mm border around the contrast enhancing lesion, there was higher signal intensity in FLAIR (p = 0.02), and T1C (p < 0.001), and there were lower intensity in ADC (p = 0.029) and DTI-p (p < 0.001). Further applying radiomics features showed that 35 first order features and 77 second order features were significantly different between progression and non-progression areas. By using supervised convolutional neural network, there was an overall accuracy of 92.4% in the training set (n = 37) and 78.5% in the validation set (n=14). In summary, multimodal MR imaging, particularly diffusion tensor imaging, can demonstrate distinct characteristics in areas of potential progression on preoperative MRI, which can be considered potential targets for treatment. Further application of radiomics and machine learning can be potentially useful when identifying the tumor invasive margin before the surgery.

Orientador: Sandra Aparecida Drigo Linde / Resumo: Introdução: Apesar dos avanços no tratamento, cerca da metade dos pacientes com câncer de reto (CR) desenvolverá metástase à distância. No entanto, as vias biológicas envolvidas na progressão do câncer não são totalmente conhecidas. Neste estudo, investigamos os perfis moleculares e imunológicos em adenocarcinomas de reto relacionados à progressão metastática visando identificar biomarcadores moleculares e/ou alvos terapêuticos. Pacientes e Métodos: O transcritoma de 15 tecidos de CR metastático (M) e não-metastático (NM) pré-tratamento e de duas amostras de tecido de reto normais foi avaliado utilizando a plataforma Clariom D. Os genes foram considerados diferencialmente expressos quando a alteração de expressão era maior que 2 vezes e o valor de p <0,05 e detectados com o pacote limma. As funções moleculares e vias biológicas foram determinadas com a ferramenta Enricher. Os achados foram validados utilizando dados do TCGA e o perfil imunológico determinado com o algorótimo xCell. Resultados: A comparação entre os grupos M e NM revelou 52 genes diferencialmente expressos, sendo 27 regulados positivamente e 25 regulados negativamente. O gene ANLN foi detectado com o maior valor de fold change nos tumores metastáticos. Além disso, expressão aumentada de ANLN foi associada com menor sobrevida em pacientes com CR. A via do fator de crescimento endotelial vascular (VEGF) foi detectada como alterada nos tumores M. Validação dos resultados com dados do TCGA confirmou o gene ANLN co... (Resumo completo, clicar acesso eletrônico abaixo) / Abstract: Introduction: Despite advances in treatment, about half of patients with rectal cancer (RC) will develop distant metastasis. However, the biological pathways underpinning the cancer progression are not fully understood. In this study, we sought to identify molecular and immunological profiles in rectal adenocarcinomas related to metastatic progression aiming to identify molecular biomarkers and/or therapeutic targets. Patients and Methods: Transcriptome analysis of 15 pre-treatment metastatic (M) and non-metastatic (NM) rectal cancer tissues and two normal rectal tissue samples was evaluated using Clariom D platform. Genes were considered differentially expressed when presenting 2-fold change and p<0.05 and were obtained with limma package . Molecular function and biological pathways with the Enricher package. Our findings were validated from the TCGA database and the immunological profile was determined using the xCell algorithm. Results: The comparison of M with NM groups revealed 52 differentially expressed genes, being 27 up-regulated and 25 down-regulated. ANLN gene was detected as the top gene upregulated in M tumours. Additionally, ANLN overexpression was associated with shorter survival in RC patients. Vascular endothelial growth factor (VEGF) pathway was detected as altered in M tumours. Cross-study validation with TCGA dataset confirmed ANLN gene as associated with M tumours. Furthermore, KIF14, XRCC2 and GPX3 genes, which have important carcinogenesis functions, we... (Complete abstract click electronic access below) / Mestre

Nors vietinis naviko progresavimas yra esminė problema, atliekant piktybinių navikų kepenyse radijo dažnio abliaciją, dažniausiai tai yra vienintelis rodiklis, apibrėžiantis šio gydymo metodo veiksmingumą. Mūsų tyrimo tikslas buvo nustatyti kompiuterinės tomografijos ir ultragarso tyrimų bei histologinio stulpelinės biopsijos medžiagos, paimtos iš abliuoto naviko, histologinio tyrimo rezultato reikšmę anksti vertinant radijo dažnio abliacijos veiksmingumą. Tyrimo medžiaga ir metodai: Į tyrimą buvo įtraukti 68 pirminiai ir metastaziniai kepenyse esantys navikai. Radijo dažnio abliacija buvo atliekama naudojant perfuzijos elektrodus. Navikai prieš abliaciją ir po jos atliekant kontrolinius tyrimus buvo vertinami kompiuterinės tomografijos ir ultragarsinio tyrimo metodais. Po abliacijos praėjus vienam mėnesiui buvo atliekama abliacijos zonos punkcinė stulpelinė biopsija, audiniai tiriami histologiškai. Rezultatai ir išvados: Galutinei analizei buvo tinkami 58 sėkmingai gydyti navikai. Radiologinio stebėjimo metu buvo nustatyti devyni (15,5 %) vietinio naviko progresavimo atvejai. Vidutinis analizuotų navikų stebėjimo laikas buvo 16,3 mėnesiai (nuo 1,7 iki 38,7 mėnesių). Nustatyta, kad: 1. Biopsijos medžiagos, paimtos iš abliacijos zonos praėjus vienam mėnesiui po naviko, esančio kepenyse, radijo dažnio abliacijos, histologinio tyrimo rezultatas neleidžia prognozuoti vietinio naviko progresavimo 2. Naviko dydis 30 mm ir naviko lokalizacija arčiau kaip per 5 mm nuo didesnio nei 3... [toliau žr. visą tekstą] / Local tumour progression remains the main problem after radiofrequency ablation of liver tumours and it is usually the only measure of treatment efficacy. The aim of our study was to investigate and evaluate the prognostic value of computed tomography and ultrasonography as well as the histological result of core biopsy material from ablated tumour on assessment of radiofrequency ablation effectiveness. Materials and methods: We have studied 68 malignant primary and metastatic hepatic tumours treated by radiofrequency ablation. Ablation was performed using perfusion electrodes. Evaluation of tumours before ablation and follow up was performed by means of contrast enhanced computed tomography and ultrasonography. Ablation zone was biopsied for histological examination. Results and conclusions: 58 successfully treated hepatic tumours were suitable for the final analysis. The local progression of nine (15.5 %) tumours was detected on follow up. Mean follow up time for analysed tumours was 16.3 months with a range from 1.7 to 38.7 months. It was showed, that: 1. The result of histological examination of ablation zone biopsy material taken one month after radiofrequency ablation of malignant liver tumour does not predict local tumour progression. 2. Tumour size 30 mm and larger and tumour proximity closer than 5 mm to hepatic vessels larger than 3 mm are significant risk factors for local tumour progression after radiofrequency ablation of malignant liver tumours 3. Tumour type... [to full text]

Local tumour progression remains the main problem after radiofrequency ablation of liver tumours and it is usually the only measure of treatment efficacy. The aim of our study was to investigate and evaluate the prognostic value of computed tomography and ultrasonography as well as the histological result of core biopsy material from ablated tumour on assessment of radiofrequency ablation effectiveness. Materials and methods: We have studied 68 malignant primary and metastatic hepatic tumours treated by radiofrequency ablation. Ablation was performed using perfusion electrodes. Evaluation of tumours before ablation and follow up was performed by means of contrast enhanced computed tomography and ultrasonography. Ablation zone was biopsied for histological examination. Results and conclusions: 58 successfully treated hepatic tumours were suitable for the final analysis. The local progression of nine (15.5 %) tumours was detected on follow up. Mean follow up time for analysed tumours was 16.3 months with a range from 1.7 to 38.7 months. It was showed, that: 1. The result of histological examination of ablation zone biopsy material taken one month after radiofrequency ablation of malignant liver tumour does not predict local tumour progression. 2. Tumour size 30 mm and larger and tumour proximity closer than 5 mm to hepatic vessels larger than 3 mm are significant risk factors for local tumour progression after radiofrequency ablation of malignant liver tumours 3. Tumour type... [to full text] / Nors vietinis naviko progresavimas yra esminė problema, atliekant piktybinių navikų kepenyse radijo dažnio abliaciją, dažniausiai tai yra vienintelis rodiklis, apibrėžiantis šio gydymo metodo veiksmingumą. Mūsų tyrimo tikslas buvo nustatyti kompiuterinės tomografijos ir ultragarso tyrimų bei histologinio stulpelinės biopsijos medžiagos, paimtos iš abliuoto naviko, histologinio tyrimo rezultato reikšmę anksti vertinant radijo dažnio abliacijos veiksmingumą. Tyrimo medžiaga ir metodai: Į tyrimą buvo įtraukti 68 pirminiai ir metastaziniai kepenyse esantys navikai. Radijo dažnio abliacija buvo atliekama naudojant perfuzijos elektrodus. Navikai prieš abliaciją ir po jos atliekant kontrolinius tyrimus buvo vertinami kompiuterinės tomografijos ir ultragarsinio tyrimo metodais. Po abliacijos praėjus vienam mėnesiui buvo atliekama abliacijos zonos punkcinė stulpelinė biopsija, audiniai tiriami histologiškai. Rezultatai ir išvados: Galutinei analizei buvo tinkami 58 sėkmingai gydyti navikai. Radiologinio stebėjimo metu buvo nustatyti devyni (15,5 %) vietinio naviko progresavimo atvejai. Vidutinis analizuotų navikų stebėjimo laikas buvo 16,3 mėnesiai (nuo 1,7 iki 38,7 mėnesių). Nustatyta, kad: 1. Biopsijos medžiagos, paimtos iš abliacijos zonos praėjus vienam mėnesiui po naviko, esančio kepenyse, radijo dažnio abliacijos, histologinio tyrimo rezultatas neleidžia prognozuoti vietinio naviko progresavimo 2. Naviko dydis 30 mm ir naviko lokalizacija arčiau kaip per 5 mm nuo didesnio nei 3... [toliau žr. visą tekstą]

A better understanding of tumour heterogeneity is central for accurate diagnosis, targeted therapy and personalised treatment of glioblastoma patients. This thesis aims to investigate whether pre-operative multi-parametric magnetic resonance imaging (MRI) can provide a useful tool for evaluating inter-tumoural and intra-tumoural heterogeneity of glioblastoma. For this purpose, we explored: 1) the utilities of habitat imaging in combining multi-parametric MRI for identifying invasive sub-regions (I & II); 2) the significance of integrating multi-parametric MRI, and extracting modality inter-dependence for patient stratification (III & IV); 3) the value of advanced physiological MRI and radiomics approach in predicting epigenetic phenotypes (V). The following observations were made: I. Using a joint histogram analysis method, habitats with different diffusivity patterns were identified. A non-enhancing sub-region with decreased isotropic diffusion and increased anisotropic diffusion was associated with progression-free survival (PFS, hazard ratio [HR] = 1.08, P < 0.001) and overall survival (OS, HR = 1.36, P < 0.001) in multivariate models. II. Using a thresholding method, two low perfusion compartments were identified, which displayed hypoxic and pro-inflammatory microenvironment. Higher lactate in the low perfusion compartment with restricted diffusion was associated with a worse survival (PFS: HR = 2.995, P = 0.047; OS: HR = 4.974, P = 0.005). III. Using an unsupervised multi-view feature selection and late integration method, two patient subgroups were identified, which demonstrated distinct OS (P = 0.007) and PFS (P < 0.001). Features selected by this approach showed significantly incremental prognostic value for 12-month OS (P = 0.049) and PFS (P = 0.022) than clinical factors. IV. Using a method of unsupervised clustering via copula transform and discrete feature extraction, three patient subgroups were identified. The subtype demonstrating high inter-dependency of diffusion and perfusion displayed higher lactate than the other two subtypes (P = 0.016 and P = 0.044, respectively). Both subtypes of low and high inter-dependency showed worse PFS compared to the intermediate subtype (P = 0.046 and P = 0.009, respectively). V. Using a radiomics approach, advanced physiological images showed better performance than structural images for predicting O6-methylguanine-DNA methyltransferase (MGMT) methylation status. For predicting 12-month PFS, the model of radiomic features and clinical factors outperformed the model of MGMT methylation and clinical factors (P = 0.010). In summary, pre-operative multi-parametric MRI shows potential for the non-invasive evaluation of glioblastoma heterogeneity, which could provide crucial information for patient care.